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Lecture 5. Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place. Lecture 5 – Thursday. Block 1: Mole Balances Block 2: Rate Laws Block 3: Stoichiometry
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Lecture 5 Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place.
Lecture 5 – Thursday • Block 1: Mole Balances • Block 2: Rate Laws • Block 3: Stoichiometry • Stoichiometric Table: Flow • Definitions of Concentration: Flow • Gas Phase Volumetric Flow Rate • Calculate the Equilibrium Conversion Xe
Review Lecture 2 ReactorMole Balances Summary in terms of conversion, X X Batch t CSTR X W PFR PBR
Review Lecture 3 Algorithm How to find Step 1: Rate Law Step 2:Stoichiometry Step 3: Combine to get
Review Lecture 3 Reaction Engineering Mole Balance Rate Laws Stoichiometry These topics build upon one another
Flow System Stoichiometric Table Where: and Concentration – Flow System
Stoichiometry Concentration Flow System: LiquidPhase Flow System: Flow LiquidPhase Liquid Systems etc.
Liquid Systems If the rate of reactionwere thenwewouldhave This gives us
StoichiometryforGas Phase Flow Systems Combining the compressibility factor equation of state with Z = Z0 Stoichiometry: Weobtain:
StoichiometryforGas Phase Flow Systems Since , Using the same method,
StoichiometryforGas Phase Flow Systems The total molar flow rate is: Substituting FT gives: Where
For Gas Phase Flow Systems Concentration Flow System: Gas Phase Flow System:
For Gas Phase Flow Systems If –rA=kCACB This gives us FA0/-rA X
Example: Calculating the equilibrium conversion (Xef) for gas phasereaction in a flow reactor Consider the following elementary reaction where KC=20 dm3/mol and CA0=0.2 mol/dm3. CalculateEquilibriumConversion or both a batch reactor (Xeb) and a flow reactor (Xef).
Gas Flow Example (Xef) Rate Law: Solution:
Gas Flow Example (Xef) Stoichiometry: Gas isothermal T=T0 Gas isobaric P=P0
Gas Flow Example (Xef) Pure A yA0=1, CA0=yA0P0/RT0, CA0=P0/RT0 At equilibrium: -rA=0
Gas Flow Example (Xef) Recall Flow: Batch: